Internet Protocol version 4 (IPv4) is one addressing methodology used to route traffic across the Internet. Communication protocols may use respective identifiers assigned to each device on the communication network. The number of identifiers may be limited to certain range. For example, Internet Protocol version 4 (IPv4) uses a 32-bit address space for identifiers for devices on a communications network.
Unfortunately, the use of a limited number of identifiers means that exhaustion of identifiers can occur, which creates a variety of problems. IPv4 has a theoretical limit of approximately 4 billion unique addresses. Of these, 17,891,328 addresses (or approximately 0.4% of unique IP address under IPv4) (RFC 1918) are reserved for use in private network addressing. The remaining addresses are allocated to publicly-accessible devices such as devices on the Internet. The reason for this allocation of network addresses is to avoid address conflicts between devices on the Internet and devices in a private network.
With the rapidly increasing use of Internet connected devices and mobile devices including smartphones and tablets, the number of addresses allocated for private network addressing is becoming insufficient. For example, large service providers may exhaust the number of available private network IP addresses.